Electric heater.



F. R.WHITTLESEY. ELECTRIC HEATER.

APPLICATION FILED 001 .7, 1913. v

1,1 12,582. Patented Oct. 6, 1914.

WI M58858 [NYE/V703 B) I if: 4M225.

A HORNE) i use it known that I, FRANK R. weimt UNITED snares ra'rnnrOFFICE.

FRANK IR. WHITTL ESEY, OLE GARLAND, CALIFORNIA.

niinc'r arc Hearse.

1 '0 an whom it may concern:

sleigh citizen of the United States, residing at Oakland, in the countyOff rlrlameda and State of California, have invented certain new anduseful Improvements in Electric Heaters, of which the following is aspecilfication. v

M invention relates tothe general class of e ectric-heatersl It isadapted for heatin devices of various kinds, but particular y for thosewhich, from the nature of their use, such, for example, as radiators forWarmin rooms and articularl as'Cookers, require to receive and to impartdiil'er' ent degrees of heat, according to circumstances. a

Theobjeot of my invention is to provide a simple and efi'ectiveelectrimheatcr'for these and like purposes; and to this end my inventionconsists in the novel heater which I shall now fully describe byreference to the accompanying drawings, in which- Figure 1 is aperspective view of my heater. Fig.2 is a perspective view of theheating member showing its grooved upper face. Fig. 3 is a bottom planofthe heat.-

ing member showing its grooved lower face.

Fig. 4; is a section, enlarged, through the heating member on the linem-w of this figure showing also, in. section, the 1nclosing box andtheasbestos protection of the heating wire.

;1 is theheating member. consists er a plate or body low electricandheat conductivity. It may be of any suitable mate-- rial or combinationof materials having such property. In practical employ aslab oi Portlandcement or concrete. In this plate 1, in its upper surface, as seen inFig. 2,

are formed. the grooves for the electric heating Wire, and in its lowersurface, as seen in Fig. 3, are formed similar grooves 3. In case aconcrete slab is vised, these grooves are host molded in the material.The grooves inay be directed in any suitable extensive, tortuous course,in order to cover practically the superficial area of the slab. Ihcy arebest formed in the continuous return or zi-g-zag course shown. In theupper face the groove 2 begins at one end of the slab, asshjown in Fig.2, and thence extendstback "and forth, with its turns near but notreaching nor exposed to the ends, to the opposite side of the slab whereit Mons out in the same end. or? the or the same end in which the lPatented Oct; 6, 1914,

down in said end and joins the beginning of the groove 3 of the lowerface, by means of a short vertical groove 4 in said end. The lowergroove, 3, 'as shown in Fig. 3, returns in the'lower face of the slab insimilar manner, to the first side, where it opens out in started. t 5 isthe wire for conducting the electric current. It starts in the groove 2at its beupper groove ginning and is then laid throughout the,

course of said groove, thence passes down the vertical connecting groove4 to the lower groove 3, in which it returns to the exit of said lowergroove.

In the end of the slab 1, atthe beginning of the groove 2 is made thepermanent electricalconnection, indicated at the point 6 in Fig. 1, withthe beginning of the heating wire 5. 'In the end of the slab at theopposite side of said end is a socket 7 adapted to receive an electricplug connection with the wire 5 as it passes down in the vertical 1connecting groove 4. In the same end of the slab at one or more pointsbetween its sides,

here shown, for the sake ofillustration,-as

at one point, is a socket 8 for the reception of an electricplug-connection, with the lower wire course'i'n the lower groove 3.Finally at the first side of the slab end is ncction with the issuingend of the heating WlYG I I' 10 indicates asbestos or other-likematerial a socket 9 to receive an electric plug confor sealing the wire"5 in its grooves and protecting it from contact with the exterior casingor box of the slab.

11 is an iron casing or box with legs 12. This box comprises a bottomand sides and ends, the latter rising above the slab and re ceivingbetween them the removable iron top-plate 13. In one end of this box aremade openings 14 which register with the several sockets in the slabend, so that the plug connections, heretofore mentioned, can be made.

15 is a double electric cord leading from the source of electriccurrent. The. end of one cord is permanently connected at 6, in Fig. 1,with the beginning of the wire 5. The other cord carries a plug 16,adapted to fit any of the sockets 7, 8 or 9. When the plug 16 is fittedto the socket 7, the electric the plug 10 is fitted to the socket 9, thecurrent [lows through both upper and lower wire ,eourses, and having thegreatest resistance will give to the slab 1, the lowest heat. 'lzen saidplug 16 is fitted to the socket 8, the current will flow through a partonly of the lower wire course and through the entire upper course, andwill impart to the slab an intermediate heat. Therefore, in operatingthe device, different heats may be obtained, as desired. For example, inusing the deviici as a cooker, the )lug 16 will first be fitted to thesocket 7 so that the slab 1 may be quickly and highly heated. Then, whensultieiently heated, the slab, on account of its low conductivity andits ability to retain heat, may well have its heat increment reduced,and this may be done by fitting the plug to the socket S, or, in casethe lowest heat be sulfieient, the plug will be inserted in the socket9.

I claim '1. An clectric-neater comprising a heating member of lowelectric and heat condnc-,

tivity, said member having formed in its upper and lower faces acontinuous tortuous groove the ends of which emerge from the member atone end near one side thereof, one above the other, and the middleportlon passing from the upper to the lower face in said end near theother side thereof, said end beingformed with pluga'eceiving, sockets zt the ends of the groove and at points intermediate said ends; anelectric wire seated in said groove and exposed for electrical contactin the sockets of said member; a double electric cord one cord of whichis electrically connected with the beginning of theelectricheating-wire; and a plug carried by the other cord adapted to befitted at will to any of the sockets of the l'ieating member, to makeelectrical contact with the heating wire at various points in the lengthof said wire.

2. An electric-limiter comprising a heating member of low electric andheat conductivity, said member having formed in its upper and lowerfaces a continuous tortuous groove the ends of which emerge from themember at one end near one side thereof, one above the other, and themiddle portion passing fronithe upper to the lower face in said end nearthe other side thereof, said end being formed with plug-receivingsockets at the ends of they groove and at points intermediate said ends;seated in said groove and exposed for electrical contact in the socketsof said memher; a metallic box" inclosingsaid heating member saidboxhaving openings registering with the sockets ofisaid. member; means forinsulating the-heating Wire from the metallic box; a double electriccord one cord of which is electrically connected with the beginning oftheelect1'ic-heating-wire; and a plug carried by the other cord adaptedto be fitted at heating member, to make electrical contact with theheating wire at various points in the length of said wire.

An electric heatercomprising a substantially rectangular block formed oneach of its faces with a tortuous groove, the groove of one facecommunicating with the groove of the other face, a heating wire lying insaid groove, a casing receiving the block, a closure for the casing, afilling of asbestos 'intcrposed between the faces of the block and thecasing, said asbestos entering the grooves formed in said faces, therebeing openings formed in the casing which aline with openings formed. inthe edges of the block whereby to permit of the insertion of,

an electric connection to effect a connection with the heating wire atdifferent points throughout itslen th' to increase or diminish theresistance,

In testimony whereof I have signed my name to this specification inthcpresence of two subscribing witnesses.

' FRANK R. WI-IITTLESEY. Witnesses:

WM. F. BoorH,

S. Consrmn.

an electric wire' will to any of the sockets of the-

